The present invention relates to improvements in machinery slot covers that are used in a variety of applications including but not limited to fork lifts, medical diagnostic equipment and other applications having an arm travels along an opening or slot in a column or tube.
Arms moving along an opening or slot in a column or tubular member are common in a number of industrial applications. One well known example of such arms is found on a fork lift truck. Another example is found in medical diagnostic devices such as some scanning equipment. In these scanning devices, for example, a patient lies on a bed and a diagnostic device on an arm travels along a path to scan the patient. Other applications include the field of robotics where a moving arm may be performing a task and travel in a slot in the device. In many of these applications there is a load bearing arm that travels along a slot or opening in a column. The arm rides on a carriage over one or more tracks or other means in the column.
One of the problems encountered in, for example, fork lift applications is the problem of dirt and debris entering the slot in the column where the arm travels ultimately causing problems in the operation of the fork lift. Fork lifts are frequently used in a warehouses or storage buildings which have a significant amount of debris and dirt present. In addition, significant amounts of dust can be generate in the working environments of these devices. These deleterious materials have a tendency to enter the slot in the column and cling to the interior of the column, thus creating undue wear on the moving parts and other problems in the operation of A the arm. This problem is particularly acute where you have lubricants present on open surfaces in the interior of the column to facilitate movement of the arm in the slot. These lubricants have a tendency for attracting any dirt or debris which becomes attached to the lubricated parts due to the adhesive nature of the lubricants. This dust and debris can increase wear of critical moving parts.
Fork lifts, in many applications are also used outside where the arm and the slot are subjected to the environment, particularly moisture. In these situations the slot provides an entrance way for moisture that can cause oxidation of critical parts and reduce the useful life span of the equipment. In medical applications, besides the issue of undesirable material entering into the slot there is also the problem that the interior of the column can not be readily cleaned and disinfected. These recesses will provide a resting place for the dirt and debris that is often inaccessible. This dirt and debris will have a tendency to harbor germs that may spread throughout the facility. Similarly, in many applications where robotic arms are used there are similar issues with undesirable material entering into the slot in which the carriage travels.
In addition to these problems, there is also a major safety issue for equipment having a carriage or other mechanism traveling in a slot in a column. The unprotected opening can attract fingers and hands that could be injured if the machine is in operation while the hands are present. Many times significant forces can develop as an arm or other device travels in the slot that could crush or sever fingers caught in the slot.
One approach to solve the problem of the open slot in a column has been to provide a brush member that is attached on one side of the slot and has its bristles extend over the slot toward the other side of the slot. Alternatively, there may be a pair of brush members that are attached to each edge of the slot with their bristles extending toward the center of the slot. The brush members use the bristles of the brush as a means to block the opening and prevent foreign material from entering the slot. The brush bristles are sufficiently flexible to permit the arm mechanism to travel along the slot. The problem with the use of a brush is that the individual bristles give the illusion of sealing the opening but in reality do not. Fingers and hands can still be injured during use because the opening is still at least partially opened to the exterior. With respect to debris and foreign matter entering the slot, the fingers create a problem in that there are considerable numbers of individual bristles. Each of these bristles provides a surface for dirt and grime to rest and can create a health hazard in those applications where a clean surface is required.
It is an object of the present invention to provide a cover that effectively seals the opening of a slot in a column having a moving arm.
It is an object of the present invention to provide a cover that permits an arm to travel in a slot in a column without permitting dirt and debris to enter the slot.
It is an object of the invention to provide a cover for an opened slot containing a moving member that travels along the slot that provides protection to workers and prevents hands, and fingers, clothing tools and equipment from becoming caught in the slot.
It is an object of the invention to provide an improved fork lift having a mechanism that travels in a slot that is protected from the environment.
It is an object of the invention to provide an improved medical diagnostic device having arms that travels in a slot that is protected from the environment.
It is an object of the invention to provide a robotic arm that travels along a slot in a tubular member without permitting dirt and debris to enter the slot.
The present invention is directed to improvements in machinery slot covering mechanism that are used in a variety of applications including but not limited to fork lifts, medical diagnostic equipment and other applications having an arm travels along an opening or slot in a column or tube. According to the present invention there is an improved cover for a mechanism having an open slot along which a member travels.
A fork lift truck has a fork that travels from lowered position to pick up a load to a carrying position where the fork is raised to a suitable height. The lift assembly in a fork lift truck typically includes one or a plurality of forwardly extending fork prongs. The fork prongs are attached to carriage by an accessory mounting means. The accessory mounting means may be used for attaching the prongs or any other suitable article that can be moved by the carriage as it moves.
A mast houses a carriage that raises and lowers the accessory mounting means. The mast can be, for example, a generally tubular member or column having a pair of sidewalls that join a rear wall to a front wall. The front wall typically has an opening or slot that is frequently in the form of a narrow rectangle although other shapes are possible. The front wall forms a top member and a bottom member which are joined together by a pair of side members. The side members form the sides of the opening or slot and the top member and the bottom member form the top and bottom respectively. The length and design of the slot coupled with the size of the carriage and the mast determines the path of travel of the carriage within the mast. Extending from the first member toward the second side member is a first connection means. Extending from the second side member toward the first side member is second connection means. Joining the first and second connection means is slot cover.
The connection means each may have a securing surface for securing the connection means to the side member. The connection means has at least one connecting member that mates with a receiving member on the slot cover. Alternatively, the slot cover may have the connecting member that mates with a receiving member on the connection means. In a preferred embodiment of the invention the connection means has a three connecting members. The three connecting members are separated by receiving members. Similarly, the slot cover is provided with three connecting members in a preferred embodiment. The connecting members in the slot cover are also separated by receiving members.
As the carriage moves along the slot, the cover guide which is connected to the carriage also moves in the same direction as the carriage. The cover guide is generally a plate-like member being generally rectangular in configuration, although any suitable shape is possible. Support wings are on either side of the cover guide and provide a surface for connecting the accessory mount means to the cover guide. The cover guide is preferably designed so that the cover guide has a recessed portion in which the cover passes during movement of the carriage. As the cover guide moves along its path, the cover guide lifts the cover and causes the mated connecting members in the direction of travel to become separated from their respective receiving members. As the cover guide travels along the slot, the raised portion of the slot cover is pressed into engagement with the connection means by a pressure bar. The slot cover prevents ingress of debris and moisture into the mast thus eliminating the problem of the prior art designs. In addition, the slot cover prevents injury to hands and fingers due to the movement of the carriage in the slot.